Hi all. There are several old threads discussing DECIDE, and more on my site, so I don't know if there's much new to be said, but quick notes for the curious:
The full write-up is at
http://www.gamesdiner.com/decide . It discusses the full what and why, the benefits and drawbacks, the special-case considerations, etc. (The version there also addresses my failed Writing rolls in old write-ups, which I hope has cleared up some early points of confusion.)
The sweetly short version that appeared in Pyramid only addresses the most important usage scenario, defense vs bullets. It's the simple rule I'd suggest interested GMs try out. All it says is:
People can't actually track and dodge bullets. When the lead flies, don't tell the targets, "Miss... Miss... Oh, this one's going to hit! What do you do?"
Instead, tell the targets, "They're shooting at you! What do you do?"
That's all. From there, everything proceeds as you'd expect: The targets take action – Drop? Dive for cover? Dodge generically? Hold fast [to Aim, Concentrate, etc.] and hope the bullets miss? – as appropriate for a character under fire. If TH misses, then the gunfire misses, per RAW. If TH hits, then the gunfire might hit: the target checks defense, per RAW.
Nothing else to it, other than the consideration of whether to do the same for non-gunfire attacks. It's debatable. I like the effects in melee (see article), but the "why not defend?" reply that jacobmuller posted (I hadn't seen that before) is a fine explanation for GMs who'd prefer to leave melee as it is. No problem there!
But for defense vs gunfire, the above tweak is sensible and, IMO, just more
fun.
Correct. Though for me, "The Nazis open fire; what do you do!?" is exactly the decision I
want to play in combat. I find it more fun to hear the player shout "I dive for cover!", than to tell the player to wait up [and possibly do nothing] while we do some dice rolling first...
YMMV, of course!